/*
 * Copyright (C) 2003, 2004, 2005 Joe Walnes.
 * Copyright (C) 2006, 2007, 2008, 2010, 2011 XStream Committers.
 * All rights reserved.
 *
 * The software in this package is published under the terms of the BSD
 * style license a copy of which has been included with this distribution in
 * the LICENSE.txt file.
 * 
 * Created on 26. September 2003 by Joe Walnes
 */
package net.result;

import com.thoughtworks.xstream.converters.MarshallingContext;
import com.thoughtworks.xstream.converters.UnmarshallingContext;
import com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter;
import com.thoughtworks.xstream.io.HierarchicalStreamReader;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.mapper.Mapper;

import java.util.HashMap;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Map;

/**
 * Converts a java.util.Map to XML, specifying an 'entry' element with 'key' and
 * 'value' children.
 * <p>
 * Note: 'key' and 'value' is not the name of the generated tag. The children
 * are serialized as normal elements and the implementation expects them in the
 * order 'key'/'value'.
 * </p>
 * <p>
 * Supports java.util.HashMap, java.util.Hashtable and java.util.LinkedHashMap.
 * </p>
 * 
 * @author Joe Walnes
 */
public class MapConverter extends AbstractCollectionConverter
{

	public MapConverter(Mapper mapper)
	{
		super(mapper);
	}

	public boolean canConvert(Class type)
	{
		return type.equals(HashMap.class) || type.equals(Hashtable.class) || type.getName().equals("java.util.LinkedHashMap") || type.getName().equals("sun.font.AttributeMap");
	}

	public void marshal(Object source, HierarchicalStreamWriter writer, MarshallingContext context)
	{
		Map map = (Map) source;
		for (Iterator iterator = map.entrySet().iterator(); iterator.hasNext();)
		{
			Map.Entry entry = (Map.Entry) iterator.next();

			writer.startNode((String) entry.getKey());
	
			context.convertAnother(entry.getValue());
			writer.endNode();
		}
	}

	public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context)
	{
		Map map = (Map) createCollection(context.getRequiredType());
		populateMap(reader, context, map);
		return map;
		
	}

	protected void populateMap(HierarchicalStreamReader reader, UnmarshallingContext context, Map map)
	{
		populateMap(reader, context, map, map);
	}

	protected void populateMap(HierarchicalStreamReader reader, UnmarshallingContext context, Map map, Map target)
	{
		while (reader.hasMoreChildren())
		{
			reader.moveDown();
			putCurrentEntryIntoMap(reader, context, map, target);
			reader.moveUp();
		}
	}

	protected void putCurrentEntryIntoMap(HierarchicalStreamReader reader, UnmarshallingContext context, Map map, Map target)
	{
		reader.moveDown();
		Object key = readItem(reader, context, map);
		reader.moveUp();

		reader.moveDown();
		Object value = readItem(reader, context, map);
		reader.moveUp();

		target.put(key, value);
	}

}
